title: Fine tuning the LightOn light-switchable transgene expression system.
abstract: Spatiotemporal control of transgene expression in living cells provides new opportunities for the characterization of gene function in complex biological processes. We previously reported a synthetic, light-switchable transgene expression system called LightOn that can be used to control gene expression using blue light. In the present study, we modified the different promoter segments of the light switchable transcription factor GAVPO and the target gene, and assayed their effects on protein expression under dark or light conditions. The results showed that the LightOn system maintained its high on/off ratio under most modifications, but its induction efficiency and background gene expression level can be fine-tuned by modifying the core promoter, the UASG sequence number, the length of the spacer between UASG and the core promoter of the target protein, and the expression level of the GAVPO transcription factor. Thus, the LightOn gene expression system can be adapted to a large range of applications according to the requirements of the background and the induced gene expression.
authors.affiliation: Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, School of Pharmacy, East China University of Science and Technology, Mei Long Road, Shanghai 200237, China.
authors.forename: Zhengcai
authors.initials: Z
authors.lastname: Ma
authors.forename: Zengmin
authors.initials: Z
authors.lastname: Du
authors.forename: Xianjun
authors.initials: X
authors.lastname: Chen
authors.forename: Xue
authors.initials: X
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D005786:Gene Expression Regulation / Q000528:radiation effects*; D057809:HEK293 Cells; D006801:Humans; D008027:Light; D061986:MCF-7 Cells; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000528:radiation effects*; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000528:radiation effects*; D019076:Transgenes / Q000235:genetics / Q000528:radiation effects*
chemical_list: D014157:Transcription Factors
keywords: Background expression; Gene expression; Induction efficiency; Light